The human SWI/SNF subunit Brm is a regulator of alternative splicing.
The SWI/SNF (mating-type switch/sucrose nonfermenting) complex involved in chromatin remodeling on promoters has also been detected on the coding region of genes. Here we show that SWI/SNF can function as a regulator of alternative splicing. We found that the catalytic subunit Brm favors inclusion of variant exons in the mRNA of several genes, including E-cadherin, BIM, cyclin D1 and CD44. Consistent with this, Brm associates with several components of the spliceosome and with Sam68, an ERK-activated enhancer of variant exon inclusion. Examination of the CD44 gene revealed that Brm induced accumulation of RNA polymerase II (RNAPII) with a modified CTD phosphorylation pattern on regions encoding variant exons. Altogether, our data suggest that on genes regulated by SWI/SNF, Brm contributes to the crosstalk between transcription and RNA processing by decreasing RNAPII elongation rate and facilitating recruitment of the splicing machinery to variant exons with suboptimal splice sites.
Pubmed ID: 16341228 RIS Download
Adaptor Proteins, Signal Transducing | Alternative Splicing | Antigens, CD44 | Cell Line, Tumor | DNA-Binding Proteins | Exons | Humans | Phosphoproteins | Phosphorylation | Protein Binding | Protein Subunits | RNA Polymerase II | RNA, Small Nuclear | RNA-Binding Proteins | Transcription Factors